Regulating device



511151. 17, 1935. y E. FISCHEL 2,014,965

REGULATING DEVICE Filed' Jan. 31, 1954 z sheets-sheet 1 Sept.. 17,1935. E, FlsCl-IEL v 2,014,965

REGULATING DEVICE Filed Jan. 3l, 1954 2 Sheets-Sheet 2 37!l 37 37 4'0 44 .5l 37 43 l 45 e #la :37% dfvuwlwf( ATTO/WYE f Patented ept. 117, 1935 'PATENT oFFlcE 2,014,965 'REGULATI'NG DEVICE Eduard Fischel, Berlin-CharlottenburgfGermany,

assigner to Siemens-Apparate und Maschinen G. m. b. H., Berlin, Germany, a corporation of Germany Application January 31, 1934, Serial No. 709,197

In Germany February 3, 1933 4 ciaims.- (cian-2m I *l e invention relates Ito a regulating-device.

regulating systems itv may be .effected by retrieving the regulating' device by the adjustable regulating member, that the oscillations about the desired value are continuously' decreasing. In these devices the damping of the oscillations will be the better, the more the whole lregulating system is unbalanced. Therefore it 1s necessary, to forego to a closely aperiodic reach` llI.y ing of the desired value, if this value is to be maintained constant with high accuracy. It is known to use beyondthe rate of deviation from the desired value also other controlling values,

according to which the regulating member will be adjusted with the eiect of stronger damping of the oscillations. lMoreparticularly it has been proposed to 'determine not only the deviations from the desired value but also the rate of -termined by a separate instrument. Not in al1- cases is it possible or desirable to'adopt this way of determining the rate of change, but it is betterA and more simple inconstruction to derive 4the rate of change from the measured changes of the desired value.

According-to this invention the rate of change of the desired value to be maintained,l and, as the case may, also further-derivatives of .the said desiredvalue are obtained by means ,of Vone or more diii'erentia'tingdevices which are directlyV influenced by the .normally vmeasured value. lmaintained on a constant rate by means of the regulating device, may be of any kind, for example, an angle-value, a velocity, an electric current or voltage, a temperature or the like. The invention will be better understood from several embodiments, diagrammatically shown in the drawings in which Fig. 1 represents an automatic steering device for aircrafts-iniluenced by an instrument measuring lthev relative velocity of aircraft,

Fig. 2 represents the automatictregulating of 5 'the velocity of a machine; l

This value to be measured and to bev Fig. 3 represents a somewhat altered part of Figs. 1 and 2 for electrically differentiating the controlling value,

Fig. 4 shows another embodiment for regulating the stability of aircrafts.

In Fig. lthe diaphragm I of a di'ierential-manometer is influenced on the one side by a pressure proportional to the velocity of the aircraft relatively to the air', which pressure may be o tained by a Venturi-nozzle or the like. On l0 other side the diaphragm I is urged by a spring 2 according to the velocity to be maintained by the aircraft. This spring 2 is connected with its one end to the diaphragm I and with its other l end to a nut 4, provided with' pins sliding in 15 guiding slots of a member 3. The spindle 4' of Y the nut can be rotated'by means of the flexible shaft 5 with hand wheel 6. By turning this hand wheel the tension of the spring 5 may beA adjusted on a rate according to, the desired wind- 20 from the desired velocity, are transmitted to the control-needle I0 by a two-armed lever 9, fulc'rumed at 8. Within the valve-housing or cylinder II a piston I3 is slidable under the influence of a pressure medium, for instance, oil, entering 30 throughv the pipe '12. If the needle I0 is moved back relatively to the pistony I3. the duct Il of Y the piston is opened in consequence of which the pressure in the chamber I5 will drop.r As the area. of the surfacef1 `is larger than that ofthe 35 surface fz, the piston will follow the needle Il until this needle throttles the duct Il to such an extent that the two said pressures are equal. 'I'he movement of the piston I3 is transmitted by means of the rod Ito rods I'I and to the 40 i control valve 24. In this way the movements of the valve 2l are proportional to the deflections of the diaphragmnL 'I'he lrod I8 is connected with an loil-cataract or motor I 9, the damping intensity of which is adjustable bya throttle- 45 lvalve or by-pass 'valve I9'. The damping intensity-of such a cataract is, as well known, pro- `of change of the deflections of the diaphragm I.

The movement of the said piston is also transmitted to linkage I\'I, I8, 24' and to the control valve 24. according to the wind velocity of the air craft as well as according to the rat of change of this velocity, that is the acceleration of the aircraft. The piston of the hydraulic motor 25, adjusting the steering rudder 26 of the aircraft, follows thc movement of the piston of the control valve 24, thus retrieving the piston of this valve!! by means of the two armed lever I 8.

In order to increase the accuracy of vregulation a second device with a control needle may be provided in a, known manner,` which needle may be actuated by the lever Il! and will itself c ontrol a device similar to the elements I3, Il, I5, the piston of this device actuating the piston III of the arrangement shown.

In Fig. 2 part of a hydraulic regulating device for a power-machine is represented, in which the lever 9, again actuating the needle I0, is coupled with the slide 21 of a centrifugal governor 28 of a. known type. The elements III-25 are arranged and constructed in the same manner as shown in Fig. 1. In-this case the motor I9 adjusts the regulating member of the power machine in accordance with the amount of deviation and of the rate of change of the rotary speed of the machine from that speed, which is to be maintained constant.

In the arrangements described above the oilcataract or motor I9, 20 may be replaced by any other damping-device, the damping intensity of which is proportional to the speed of its movement. For instance the damping may be obtained by means of an adjustable throttle valve, arranged in one branch of the pipe I2.

Instead of the oil any' other pressure-medium, for instance air, may be used. The invention vmay be embodied in any other suitable form, an

electrical one being shown in Fig. 3.

It is assumed that the voltage or the current at the terminals 3 0 is to be maintained constant. This voltage is supplied to the primary of a transformer 3l, the secondary of which is connected to the grid-circuit of an electronic tube 32. The output of this tube is supplied to the one winding 33 of a galvanometer 33, 33 and to the primary of a transformer 35. 'Ihe secondary of this transformer 35 is connected to the grid-circuit of a second electronic tube 36, the output of which is supplied to the other winding 33' of the galvanometer 33, 33'. The two windings 33 and 33' are mechanically connected with each other and form the rotatable element of the galvanometer. As the current in the winding 33 is proportional to the voltage at the points 30 while the current in the second winding 33 is proportional to the rate of change of said voltage, the galvanometer will be deflected according to the sum of the amount of change of the initial. tension and of the rate of change of this initial tensionr The deflection of the galvanometer therefore may be used for regulating the driving machine of the generator supplying the voltage to the terminals 30.

As one modification of the described invention, further differentiating devices may be added to obtain further derivatives of the originally measured value, as the case may be.

In the arrangement according to Fig. 1 the control value, received from the differentiating device serves for damping the regulating oscillations. In case the regulating system so far described is to be used in connection with aircrafts Therefore the control valve is shifted'.

the damping of the aircrafteoscillations must be very accurate. For example in the arrangement described for stabilizing the speed of aircraft there may arise two kinds of oscillations, namely deviations from the desired relative 5 speed of the aircraft, having a longoscillation period. and pendulous movements about the transverse axis of the aircraft, having a relatively short oscillation period.v 'Ihe device shown in v Fig. l, enables the damping of only the first 10 named oscillations of long oscillation period;

, or damping the second kind of oscillations the device so far described will not be available, as the turning velocity of these oscillations will not or not sumciently be determined by the diifer- 15 entiating device.

In order to compensate the second kind of oscillations more exactly, according to a, further feature of the invention the angular velocity of the aircraft is measured and used as a control zo value additional to the aforesaid two values, that is the originally measured steering value and its first d erivative, obtained from the said differentiating device. The-angular velocity of the aircraft about its vertical axis may bev measured by a turn indica tor of well known character which is sensitive. even to very small angular movements of the aircraft and will influence the regulating in such a way that the above mentioned oscillations of 30 short periods are eliminated when arising.

If not the stabilizing of the aircraft speed but of the position of the aircraft is tobe obtained, the main control instrument may be a pendulum measuring the foreand aft-inclinations of the u aircraft, for instance a gyroscoplc pendulum or the like, which instruments again actuate the differentiating device. 'Ihe longitudinal stabilization of the aircraft may also be influenced by means for indicating w the angle of incidence of the wind relatively to the wings of the airplane. The device for measuring this angle in a known manner may consist of a cylindrical aerofoil, the symmetry plane of which is parallel with the longitudinal and 45 the transverse axes of the aircraft. This aero'- foil is arranged in the flying wind in such a' manner that the pressures in the two Jets, sym` metrically arranged with respect to the leading edge of said aerofoil; are equal as long as the 50 said symmetry planeis horizontal. However as influenced so as to determine the rate of change o of the angle of incidence.

Besides the angle of incidence and its rate of change the angular velocity of aircraft about its transverse axis may be measured by a turn indicator for influencing the rudder mechanism for 65 longitudinal stabilization.

The cooperating of the three aforesaid control values will be better 4understood from a device for longitudinal stabilization as shown in Fig. 4. The elements I-III are the same as shown 70 in Fig. 1 and described above. In the cylinder II the piston 31 is movable. Above and below the diii'erential piston 31 oil or any other presvsure medium is fed by means of the pipes 33, 39. The pipe 40 forms'the outlet of the pres- 75 transverse, iongimdinsu or i sure oil. A throttle valve 5I, arrangedin the common feeding pipe. serves for regulating 'the pressure ofthe oil. The piston 31 will follow the longitudinal movements of the needle Il. As already described with relation to Fig. 1, the function is as follows:

Ii' the needle I 0 is moving back, the throttling of the channel 31 eifected by the needle will be decreasing and in consequence of this the pressure in the chamber la will also become less. Therefore the piston 31 willfollow the needle until the needle Il throttles the channel 31 to suchan extent that the pressures acting upon the piston 31 will be balanced. The movement of the piston 31 is damped bymeans of the damping device 4I, 42. the piston 42 of which is connected to the piston 31. 'Ihe chambers above .and below the piston 42 are connected with each other by the pipe 4Ia, in which the adjustable throttle valve 4Ib is arranged. The damping cylinder may be also tothe speed ofthe piston 31.

'Within the differential piston 31 the piston 43 is arranged. The springs 44 and 45 tend to maintain .the piston 43 in its shown middle-position.

The piston-rod 43a extends through the piston 31 andis coupled with the rod 44, by means of which the longitudinal movement of the piston 31 is transmitted to the two armed lever 45. As mentioned above the damping force of the damping device 4 I 42 is proportional to the speed of the differential piston 31. Also the pressure in the chamber la'. is proportional to-the speed=of the piston 31. This pressure is communicated by means of the channel 31" to the' chamber 31"' above the piston r43, in consequence of which the piston 43 will move according to the difference of pressures, acting upon this piston through the pipes 31" and l31. As this movement takes place against the action of the one or the other of the two springs 44 and. 45, the amount of movement of piston 43A is proportional to the moving speed of the piston 31. However, as this piston is moving according to the deviations of the aircraft-speed' from the desired speed, the movement of the piston 43 will be-proportional to the sum of the said deviations and of the rst derivative of said deviations, which derivative is obtained by means of the piston 43 and corresponds to the acceleration of the aircraft-movement.

'I'he piston rod 43a may be coupled with adamping device 45, constructed like the damping device 4I'-42 and compensating or eliminating sudden loclty of the aircraft about its transverse axis.

This angular velocity is measured by aso-called turn indicator of the well-known gyroscopic type.

In the construction illustrated this turn` indicator comprises the gyroscope 45, the'rotation'axis 4l' of which is in this case arranged parallel to theA longitudinal axis 41 of the aircraft and the precesaion' axle has its horizontal bearings in the part 4l. '.lhe precessionof the gyroscope 43 is'constrained by the, springs 49,for which reason the deflection of the precession axle'41 is proportional Yiotlieangular velocity of the aircraft about its l l i a transverse axis. Thehsaid deflections are trans-l mitted to the right end of the lever 45 -by means of the lever 50. f

The algebraic sumof all three control values. vthat is the deviations -from the desired speed of aircraft, the acceleration of aircraft and the angular velocity about the transverse axis of the air- .,craft, is transmitted by, means of the rod I1 and v of the differential lever I3.

Obviously the oscillations of the aircraft-speed about the desired value set at the diaphragm I are compensated exclusively by the regulating device acting upon the left end of the lever 45, the acceleration of aircraft, obtained by this device,

serving for damping these oscillations of relatively long period. Theangular oscillations of the aircraft about its transverse axis are at once measured by the gyroscopic turn indicator .44' and damped bythe action of this turn indicator upon the rudder motor.- l

1n. an arrangement according to the invention for the transverse stabilization of aircrafts the turn indicator mustv be arranged insuch a way. that its rotation axis is parallel to the vertical axis of the aircraft and its precession axis is paralfor instance a transvers/e-fpendulum or the like. 35 The last mentioned instruments enable only a retarded measurement .of the transverse inclina-` tions of the aircraft, as on the arising of such inclinations a side slip will occur only gradually and as a pendulum often will deviate from the true vertical, if transverse or centrifugal accelerations are acting upon it. The influence of the -con` trol device acting upon the left end of the twoarmed lever would again be retarded, whilstI in this case also the turn indicator would measure 4 veven the smallest angular velocity and therefore influence the rudder motor in the direction` of preventing the said angular movements of alrcraft. l

-I claim:

aircraft from the value to be maintained constant, a differentiating device for differentiating the 25 of the altitude 10i' 4 5o 1. A regulating system for stabilizing aircrafts comprising means for measuring the deviations of vvalue measured by the beforesaid means, this differentiating device consisting of a differential plston moving in a cylinder, a control needle, a. two. part. damping device, the one part of which is in operative connection with saidV differential piston, a second piston.' a second cylinder, a com- 50 municating pipe between said two cylinders and a spring connected to said second piston,- and means for bringing about a combined action by themeasured value and itsv derivative upon the element to beadjusted in order to maintain the 35 aircraft stabilized. i

2. A regulating system for`stabilizing aircraft A comprising means for measuring the deviations of aircraft from the valueto be maintained constant,

a differentiating device for differentiatingthe said piston, a two-part damping device, one part 75,v

of which is connected to said diierential piston, a second piston, the cylinder of which is formed by said diiierential piston, a second damping' device with a piston and a cylinder, the last mentioned piston connected to the piston moving within said differential piston, the cylinder of the last mentioned damping device being connected to the diierential piston, a spring arrangement acting upon said piston moving within said differential piston, and means for bringing about a combined action by the measured value and its derivative upon the element to be adjusted in order to maintain the aircraft stabilized.

3. In a regulating system for stabilizing aircraft, the combination of means for measuring the deviations of the craft from the Value to be maintained, two communicating cylinders connected with a supply of iiuid under pressure, independently movable pistons, one in each of said cylinders, connecting the cylinderl chambers at opposite ends of such piston, a movable element controlling said passage, an operative connection from said measuring means to said movable element, dampone of said pistons having a passage ing means connected with such piston, movable mechanism having operative connections to both of said pistons to take a position responsive to the joint action of said pistons, and regulating means operated by said mechanism.

4. In a regulating system for stabilizing aircraft, the combination of means for measuring the deviations of the craft from the value to be maintained. two communicating cylinders one oi which has both oi its ends connected with a supply of .iluid under pressure, independently movable pistons, one in each oi' said cylinders, the piston which is locate'd in the cylinder connected with the supply o! iluid having a passage connecting the cylinder chambers at opposite ends of such piston, a movable element controlling said passage, an operative connection from said measuring means to said movable element, damping l means connected with such piston, movable mech- Aanism having operative connections to both oi 20 said pistons to take a position responsive to the joint action of said pistons, and regulating means operated by said mechanism.

EDUARD FISCHEL. 

